We were at the Palladium over Christmas and went to Tulum by ourselves, way less expensive than the tours. Cross the main street in front of the Palladium you'll see a palapa there, wait and a van will stop and pick you up. When you get in tell them you want the Tulum Ruins, if not they may take you right to the town of Tulum. Once you get to the ruins you can decide for yourselves if you want to hire a guide. Go early, beat the heat and the crowds.